As semiconductor devices have become highly integrated, it has become more difficult to fabricate such semiconductor devices. In particular, it becomes very difficult to form a thin film that is used in fabricating a semiconductor device, e.g. a silicon oxide layer or the like, on a substrate with adequate step coverage.
For example, in the case of forming an inter-gate dielectric layer (or a tunnel insulating layer) interposed between a charge storage layer and a control gate in a flash memory device including a plurality of memory cells (or gate stacks), a void may occur in a space between neighboring memory cells.
On the contrary, in the case of forming a silicon oxide layer through an atomic layer deposition (ALD) method using an inorganic silicon precursor such as bis(teriary-butylamine)silane (BTBAS) or the like, the step coverage may be improved, however, the layer quality of the formed silicon oxide layer may deteriorate due to carbon (C) or nitrogen (N) components included in the inorganic silicon precursor.